蓝牙数控直流电流源的设计

Design of Bluetooth digital control DC current source

普通的直流电流源输出的电流值单一,只能在特殊的场合使用,通用性不强。而可以实现多级电流输出调节的传统直流电流源往往采用电位器调节输出电流,精度差,无法实现精确步进,且输出值经常跳变,使用不便。为了精确控制输出的电流值并满足新时代环境下的用电需求,文中提出一种蓝牙数控直流电流源的设计方案。系统采用STC12C5A60S2作为主控芯片,通过按键或者蓝牙调控改变输出的数字量;通过DAC0832构成的D/A转换模块将数字量转换为模拟电压,此电压经过反相放大器放大后,输入到由运算放大器LM675组成的电压转电流电路,将电压转换为相应的电流,只要控制单片机输出的数字量即可调节输出电流值。此外,实现步进10 mA,输出电流范围为200 mA~1 A,在LCD1602液晶屏上显示输出的电流值。经测试,所设计系统的输出电流具有较高精度,输出稳定、调节方便、控制精度高、显示直观、人机交互友好,使用蓝牙还可以实现电流值的远程控制。

The output current value of ordinary DC current source is single,which can only be used in special occasions and is not universal.However,a potentiometer is used to regulate the output current in the traditional DC current source that can realize multi⁃level current output regulation,which has poor accuracy and can not achieve precise step,and the output value is variable and is inconvenient to use.In order to accurately control the output current value and meet the power demand in the new era,a design scheme of Bluetooth digital control DC current source is proposed.In the system,the STC12C5A60S2 is used as the main control chip to control and change the output digital quantity through keys or Bluetooth.The digital quantity is converted into analog voltage by means of the D/A conversion module composed of DAC0832.This voltage is amplified by the inverse amplifier,and then inputted into the voltage⁃to⁃current circuit composed of the operational amplifier LM675 to convert the voltage into the corresponding current.The output current value can be adjusted as long as the digital quantity output by the single chip computer is controlled.This system can achieve 10 mA step,output current range within 200 mA~1 A,and display the output current value on the LCD1602 screen.The testing results show that the output current of the designed system has high accuracy,stable output,convenient adjustment,high control accuracy,intuitive display,and friendly human⁃computer interaction,and the use of Bluetooth can also achieve remote control of current value.